<template>
    <div class="box">
        <vc-viewer ref="viewerRef" @ready="onViewerReady" :infoBox="false">
            <vc-terrain-provider-cesium ref="provider"></vc-terrain-provider-cesium>
            <vc-layer-imagery :alpha="alpha" :brightness="brightness" :contrast="contrast">
                <vc-imagery-provider-bing ref="provider"
                    bm-key="AmGu3cvB_g1HbkQErEyvmLc9j0YIGWS7IdOqR7-hQbO8J92Fzrzkhy_bYKSsyoEx"
                    :map-style="mapStyle"></vc-imagery-provider-bing>
            </vc-layer-imagery>
        </vc-viewer>
    </div>
</template>

<script setup>
import { ref, onMounted } from 'vue'
import { VcViewer } from 'vue-cesium'
const viewerRef = ref(null)
onMounted(() => {
    viewerRef.value.creatingPromise.then((readyObj) => {
    })
})

const onViewerReady = (readyObj) => {
    // console.log(readyObj.Cesium) // Cesium namespace object
    // console.log(readyObj.viewer) // instanceof Cesium.Viewer

}

function get_another_point(lon, lat, angle, distance) {
    // WGS84坐标系
    var a = 6378137;	// 赤道半径
    var b = 6356752.3142;	// 短半径
    var f = 1 / 298.257223563;	// 扁率

    var alpha1 = angle * (Math.PI / 180)
    var sinAlpha1 = Math.sin(alpha1);
    var cosAlpha1 = Math.cos(alpha1);
    var tanU1 = (1 - f) * Math.tan(lat * (Math.PI / 180));
    var cosU1 = 1 / Math.sqrt((1 + tanU1 * tanU1)), sinU1 = tanU1 * cosU1;
    var sigma1 = Math.atan2(tanU1, cosAlpha1);
    var sinAlpha = cosU1 * sinAlpha1;
    var cosSqAlpha = 1 - sinAlpha * sinAlpha;
    var uSq = cosSqAlpha * (a * a - b * b) / (b * b);
    var A = 1 + uSq / 16384 * (4096 + uSq * (-768 + uSq * (320 - 175 * uSq)));
    var B = uSq / 1024 * (256 + uSq * (-128 + uSq * (74 - 47 * uSq)));
    var sigma = distance / (b * A), sigmaP = 2 * Math.PI;
    while (Math.abs(sigma - sigmaP) > 1e-12) {
        var cos2SigmaM = Math.cos(2 * sigma1 + sigma);
        var sinSigma = Math.sin(sigma);
        var cosSigma = Math.cos(sigma);
        var deltaSigma = B * sinSigma * (cos2SigmaM + B / 4 * (cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM) -
            B / 6 * cos2SigmaM * (-3 + 4 * sinSigma * sinSigma) * (-3 + 4 * cos2SigmaM * cos2SigmaM)));
        sigmaP = sigma;
        sigma = distance / (b * A) + deltaSigma;
    }

    var tmp = sinU1 * sinSigma - cosU1 * cosSigma * cosAlpha1;
    var lat2 = Math.atan2(sinU1 * cosSigma + cosU1 * sinSigma * cosAlpha1,
        (1 - f) * Math.sqrt(sinAlpha * sinAlpha + tmp * tmp));
    var lambda = Math.atan2(sinSigma * sinAlpha1, cosU1 * cosSigma - sinU1 * sinSigma * cosAlpha1);
    var C = f / 16 * cosSqAlpha * (4 + f * (4 - 3 * cosSqAlpha));
    var L = lambda - (1 - C) * f * sinAlpha *
        (sigma + C * sinSigma * (cos2SigmaM + C * cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM)));

    // var revAz = Math.atan2(sinAlpha, -tmp); // final bearing

    return { lon: Number(lon) + L * (180 / Math.PI), lat: lat2 * (180 / Math.PI) };
}

</script>

<style scoped lang="scss">
.box {
    width: 100vw;
    height: 100vh;
}
</style>